For both teams, third base has been a glaring issue this year. If the Yankees (.668 OPS from 3B) and Red Sox (.564 OPS from 3B) look to upgrade at the deadline, the best available third baseman–Royals’ Mike Moustakas–could result in a bidding war between the rivals, per Jon Morosi of MLB.com.

Moustakas, enjoying a career-best offensive year, is the most intriguing Royal to monitor over the coming days. He could become the subject of a bidding war between the Yankees and Red Sox as the rivals chase the American League East title.

The Yankees are considering upgrades at third base, where Chase Headley is having one of the worst offensive seasons of his career. (He’s also committed the second-most errors of any Major League third baseman this year.) Many in the industry have expected the Yankees’ improvement to come from within, thanks to top prospect Gleyber Torres. But Torres injured his left elbow in a Triple-A game Saturday, halting (at least temporarily) his rapid progress through the Minors.

Boston’s need at third base is even more glaring, with the worst OPS at the position (.565) of any team in the Majors. Pablo Sandoval has fallen out of the everyday job, despite having two years and $37.2 million left on his contract after the current season ends. Headley, for the record, is under contract for 2018 at $13 million.

Heading into play on June 19, Moustakas owned an impressive .276/.316/.549 slash line with 18 home runs. With the Royals sitting at 33-35 through 68 games, a sell off could be on the horizon.

The AL East race is likely to come down to the final days of the season, making any one acquisition that much more important in a division that could be separated by just a few games.